Two people have died in violence at a Chinese-run sugar refinery in western Madagascar, the country's prime minister said Thursday.

"There are two dead and a part of the refinery has been destroyed," said Roger Kolo.

Madagascar police Saturday used tear gas to break up a rally by supporters of ex-president Marc Ravalomanana, who was placed under house arrest after returning from exile in South Africa.

Up to 300 people turned up for the banned protest in the capital Antananarivo, throwing stones at police cars and setting fire to cardboard boxes.

After months of post-election deadlock Madagascar's president named a new prime minister Friday, tapping the relatively unknown doctor Roger Kolo for the post.

The announcement came in a statement from president Hery Rajaonarimampianina's office.

The White House Monday urged Madagascar's new leader to form a government with the "confidence" of the population, but declined to say whether it would extend him an invitation to a Washington summit.

Madagascar's new leader, Hery Rajaonarimampianina, was sworn in Saturday after winning elections last month.

The African Union said Monday it had lifted its four-year suspension of Madagascar following democratic elections last month, the first since a 2009 coup.

The pan-African bloc's peace and security council announced "the lifting of the suspension of Madagascar" just two days after the country's new leader, Hery Rajaonarimampianina, was sworn in.

Madagascar security forces were Sunday investigating a grenade blast a day earlier that left a toddler dead and over 50 wounded just hours after the inauguration of the island's new president.

Police were still in the early stages of the investigation, police spokesman Colonel Florens Rakotomahanina told Agence France Presse, without giving any details.

A grenade explosion killed a toddler and wounded 33 people in Madagascar on Saturday just hours after the island's newly elected post-coup president was sworn in, authorities said.

The blast occurred a few hundred meters (yards) from the stadium where Hery Rajaonarimampianina was installed as the island's first post-coup elected president, a police source said.

Madagascar's new leader was sworn in Saturday after winning elections last month aimed at restoring democracy and much-needed foreign aid to the island after a 2009 coup.

Hery Rajaonarimampianina, 55, took the oath of office at a municipal stadium in the capital, calling for national unity and reaching out to political rivals to help return the Indian Ocean island nation to its past glory.

Madagascar leader Andry Rajoelina stood down Friday, symbolically handing over power ahead of his elected successor's inauguration, a move designed to steer the Indian Ocean island out of crisis.

"I wish you all success, I give you my blessing," Rajoelina said, before handing a large golden key as a symbol of power to president-elect Hery Rajaonarimampianina.

Madagascar's presidential candidates both claimed victory Saturday in run-off polls, each accusing the other of rigging the run-off as results started to trickle in.

Former health minister Robinson Jean Louis, candidate of ousted president Marc Ravalomanana, told Agence France Presse he expected to win 56 percent, while his opponent Hery Rajaonarimampianina claimed to have taken between 60 and 65 percent.